Vistaar Technologies Software Engineer Trainee Interview Questions, Process, and Tips

Multithreading is the ability of a CPU to execute multiple threads concurrently.

• Multithreading allows for better utilization of CPU resources.

• It can improve application performance by allowing multiple tasks to run simultaneously.

• Multithreading can be implemented in various programming languages such as Java, C++, and Python.

• Examples of multithreaded applications include web servers, video games, and media players.

My hobbies include hiking, playing guitar, and cooking.

• Hiking: I enjoy exploring nature trails and challenging myself physically.

• Playing guitar: I love learning new songs and improving my skills.

• Cooking: I like experimenting with different recipes and creating delicious meals.

In 5 years, I see myself as a senior software developer leading a team and working on complex projects.

• Leading a team of developers

• Working on complex projects

• Continuously learning and improving my skills

• Contributing to the growth and success of the company

I want to join DELL because of their innovative technology solutions and strong reputation in the industry.

• DELL is known for their cutting-edge technology solutions which align with my passion for software development.

• I admire DELL's strong reputation in the industry and their commitment to customer satisfaction.

• I believe joining DELL will provide me with opportunities for growth and career advancement.

Find an odd occurring number among even occurring numbers.

• Use XOR operation to cancel out even occurring numbers and get the odd occurring number.

• Iterate through the array and XOR each element with the result variable.

• The final result will be the odd occurring number.

Print the spiral order of a binary tree and matrix.

• For binary tree, use level order traversal and alternate direction for each level.

• For matrix, use four pointers to traverse in spiral order.

• Example for binary tree: 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7 -> 8 -> 9

• Example for matrix: 1 2 3 4 -> 8 7 6 5 -> 9 10 11 12 -> 16 15 14 13

Finding pairs in an array with a given sum.

• Iterate through the array and for each element, check if the difference between the given sum and the element exists in the array.

• Use a hash table to store the elements of the array and their indices for faster lookup.

• If there are multiple pairs with the same sum, return any one of them.

• If no pair is found, return null or an empty array.

Find total number of k element with given avg in an array in minimum time complexity.

• Use sliding window technique to traverse the array in O(n) time complexity.

• Maintain a sum variable to keep track of the sum of elements in the window.

• If the sum of elements in the window is equal to k times the given avg, increment the count.

• Move the window by subtracting the first element and adding the next element in the array.

Printing non-boundary elements of a binary tree

• Traverse the tree in any order (preorder, inorder, postorder)

• Check if the current node is not a boundary node (not the first or last node in its level)

• If it is not a boundary node, print its value

• Recursively traverse its left and right subtrees

Use bitwise operations to find the sum of two numbers without using mathematical operators.

• Use bitwise XOR to find the sum of two numbers without carrying.

• Use bitwise AND and left shift to find the carry.

• Repeat the process until there is no carry left.

To delete a node from a linked list when only given a reference to the node, we can copy the data of the next node to the given node and delete the next node.

• Copy the data of the next node to the given node

• Update the next pointer of the given node to skip the next node

• Delete the next node